Tool for joining sidelapped joints of deck panels

ABSTRACT

A punching tool for forming an attachment in a side-lapped seam of steel decking includes four cutting jaws each having a cutting edge. Two jaws are positioned against one side of the seam, and two jaws are positioned on the opposite side of the seam. An actuator selectively pivots the cutting edges of opposing jaws generally toward each other to a closed position, driving the cutting edges of a first pair of jaws partially past each other for cutting a first slot through the seam, and driving the cutting edges of a second pair of jaws partially past each other for cutting a second slot through the seam.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 12/287,852, filed on Oct. 14, 2008, for “Tool for JoiningSidelapped Joints of Deck Panels”, subsequently issued as U.S. Pat. No.______, which is, in turn, a divisional of U.S. patent application Ser.No. 11/351,463, filed on Feb. 10, 2006, for “Tool And Method For JoiningSidelapped Joints of Deck Panels”, which application issued as U.S. Pat.No. 7,434,314 on Oct. 14, 2008, and the benefit of such earlier filingdates is claimed hereby under 35 U.S.C. §120.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to steel decking used to formflooring and roofing diaphragms of buildings, and more particularly, toa tool for reliably fastening together sidelapped edges of adjacent deckpanels when constructing such building diaphragms.

2. Description of the Related Art

Fluted steel deck panels are well known in the art for constructingflooring and roofing of buildings. Examples of such fluted steel deckpanels are shown, for example, in U.S. Pat. Nos. 4,186,535 and4,894,967, both assigned to the assignee of the present application.Such steel deck panels are typically welded to underlying structuralsupport beams. When properly assembled, such fluted steel deck panelsprovide a cost-effective diaphragm for floors and roofs, as well asrelatively high horizontal shear values.

Such fluted steel deck panels typically include first and secondopposing sides that extend parallel to the axes of the flutes. One ofsuch sides includes an upwardly-extending male lip. The other of suchsides includes a downwardly-directed U-shaped female channel. When twoof such deck panels are placed side-by-side across a span of decking,the U-shaped female channel of one panel is engaged over, or overlappedwith, the male lip of the adjacent deck panel to interlock the adjacentsides of such panels. This side-lapped joint must then be properlysecured to prevent the side of one panel from slipping longitudinallyrelative to the side of the adjacent panel, and to prevent verticalseparation that can result from horizontal loading due to wind,earthquakes, concrete pours, and the like.

Methods for attaching the side-lapped joints of fluted steel deck panelsare well known, and include welding, button-punching, sheet metalscrews, riveting, and mechanical deformation of the metal forming suchside-lapped joint. For example, in U.S. Pat. No. 182,193 issued in 1876,Holeton discloses a method of forming triangular notches in theside-lapped joint and then folding over such triangular notches tointerlock the joint. In U.S. Pat. No. 3,641,729, inventor Irvindiscloses the use of lip-clenching dies operated by a clinching tool tocut a slit through the side-lapped joint, and to form opposing lobes forsecuring the side-lapped joint.

In many instances, side-lapped joints of a steel deck diaphragm must beinspected for consistency and integrity before further construction of abuilding may proceed. To avoid construction delays, it is desirable toform such side-lapped joints in a manner that allows such joints to beinspected quickly and easily, preferably from the top side of thedecking.

One apparatus for forming the side-lap attachments which has met withsome success is described in U.S. Pat. No. 6,212,932, entitled“Pneumatic Shear For Forming Structural Louvers”. In this patent, apneumatically-operated tool selectively opens and closes a pair of jawsthat are pivotally connected to each other about a common pivot axis.One such jaw includes a single blade having first and second opposingsides forming first and second blunt edges. The second jaw includes twospaced blades that are spaced from each other by the thickness of thesingle blade on the first jaw, also having blunt edges. Thus, the twospaced blades on the second jaw form a “die” for receiving the singleblade on the first jaw when the first and second jaws are pivoted totheir closed position. With the jaws in their opened position, the firstand second jaws are inserted over a side-lapped seam of a steel deck.The pneumatic tool is then activated to close the jaws toward eachother. The single blade of the first jaw passes between the two “die”blades of the second jaw, forming a pair of cuts in the overlapped seam.Further closing of the jaws deforms a central tab in a first direction,while deforming regions on either side of the central tab in theopposite direction. Side-lapped joints formed by use of this apparatushas been shown to securely fasten the side-lapped seams and tosatisfactorily resist deformation due to horizontal shear loading.

However, applicant has learned that the apparatus disclosed in U.S. Pat.No. 6,212,932 is subject to breakage when used on heavier gage decking.The single blade provided on the first jaw is subjected to significantstress, as it simultaneously forms two cuts through the overlappedmaterial at the side-lapped seam. In other words, one edge of suchsingle blade forms a first cut in cooperation with a first of the twoblades on the second jaw, and the second edge of such single blade formsa second cut in cooperation with the second of the two blades on thesecond jaw. Because of the significant stress borne by the single bladeof the first jaw, such single blade can break, necessitating a stoppageof construction and associated scheduling delays for the user. Inaddition, such breakage is a significant cost to the tool manufacturer,and related warranty claims detract from the manufacturer's profits.

Accordingly, it is an object of the present invention to provide apunching tool for forming an attachment in an interlocking side-lappedseam of a steel deck structure which provides a solid attachment capableof resisting significant horizontal shear loads.

It is a further object of the present invention to provide such apunching tool which can be operated relatively quickly and easily by adeck installer to attach interlocking side-lapped seams of a steel deckstructure.

It is a still further object of the present invention to provide such apunching tool which produces an attachment that can be quickly andeasily inspected by an inspector standing atop the assembled steeldecking.

Another object of the present invention is to provide such a punchingtool having a blade assembly that equalizes the wear on the blades, andwhich avoids excessive stress on any particular blade, to extend theusable life of the tool.

Still another object of the present invention is to form a sidelappedseam attachment that provides higher shear values by forming anattachment which is more resistant to slippage when subjected to ahorizontal load along the longitudinal axis of the sidelapped seam.

Yet another object of the present invention is to provide an improvedmethod of forming such a sidelapped seam attachment.

These and other objects of the present invention will become moreapparent to those skilled in the art as the description of the presentinvention proceeds.

SUMMARY OF THE INVENTION

Briefly described, and in accordance with the preferred embodimentsthereof, the present invention relates to a punching tool for forming anattachment in an interlocking side-lapped seam formed between first andsecond steel deck panels of a steel deck structure. As is conventional,the first steel deck panel includes an upturned male lip along one sideedge thereof; the second steel deck panel includes a downwardly-directedU-shaped female channel along one side edge thereof for receiving theupturned male lip of the first steel deck panel. The downwardly-directedU-shaped female channel of the second steel deck panel includes firstand second spaced walls.

The punching tool of the present invention includes first, second, thirdand fourth jaws. The first jaw has a cutting edge for engaging the firstwall of the female channel, and the second jaw has a cutting edge forengaging the second wall of the female channel. The second jaw isdisposed proximate to the first jaw and generally faces the first jaw,but is laterally offset therefrom, thereby allowing their respectivecutting edges to at least partially slide past one another when the jawsare closed.

An actuator is coupled to the first and second jaws for selectivelymoving the cutting edges of the first and second jaws generally towardeach other to a closed position, or away from each other to an openposition. In the preferred embodiment, the actuator is poweredpneumatically or hydraulically, though it might also be powered by anelectric motor. As the actuator moves the first and second jaws towardeach other, the cutting edges of the first and second jaws at leastpartially pass each other for cutting a first slot through the U-shapedchannel and the male lip inserted therein.

The punching tool also includes a third jaw having a cutting edge forengaging the first wall of the female channel, preferably spaced apartfrom the first jaw already mentioned above. In addition, the punchingtool includes a fourth jaw having a cutting edge for engaging the secondwall of the female channel. This fourth jaw is disposed proximate to thethird jaw, and generally facing the third jaw, but laterally offsettherefrom, thereby allowing their respective cutting edges to at leastpartially slide past one another when the jaws are closed.

The actuator already mentioned above is also coupled to the third andfourth jaws for selectively moving the cutting edges of the third andfourth jaws generally toward each other to a closed position at the sametime that the actuator moves the cutting edges of the first and secondjaws generally toward each other to the closed position. Similarly, theactuator moves the cutting edges of the third and fourth jaws away fromeach other to an open position at the same time that the actuator movesthe cutting edges of the first and second jaws away from each other tothe open position. The cutting edges of the third and fourth jaws atleast partially pass each other as the actuator moves the third andfourth jaws to the closed position for cutting a second slot through theU-shaped channel and the male lip received thereby; this second slot islaterally spaced from the first slot cut by the first and second jaws.

The cutting edges of the first and second jaws are moved by the actuatorwithin first and second planes, respectively. In one preferredembodiment of the invention, these first and second planes are generallyco-planar for allowing the respective cutting edges to pass very closelyto each other. Likewise, the cutting edges of the third and fourth jawsare moved by the actuator within third and fourth planes, respectively,and in one preferred embodiment, the third and fourth planes aregenerally co-planar for allowing the respective cutting edges to passvery closely to each other. In an alternate embodiment, the first andsecond planes, and the third and fourth planes, are intentionally spacedapart from each other to increase twisting deformation along the cutlines formed in the seam.

In its preferred form, the punching tool of the present invention mountsthe first, second, third and fourth jaws for rotation about a commonpivot axis. The first and third jaws are preferably coupled to eachother for synchronized pivotal movement. Similarly, the second andfourth jaws are preferably coupled to each other for synchronizedpivotal movement. In the preferred embodiment, the second jaw isdisposed generally between the first and third jaws, and the third jawis disposed generally between the second and fourth jaws.

Preferably, one or more of the jaws are beveled. For example, the firstjaw includes a first side forming the cutting edge thereof and also anopposing second side that forms a non-cutting edge; the first jaw isbeveled from its cutting edge to its non-cutting edge. As a result, whenthe actuator closes the jaws, the first jaw displaces the male lip andfemale channel more significantly proximate its cutting edge thanproximate its non-cutting edge. Similarly, the second jaw preferablyincludes a first side forming its cutting edge and an opposing secondside forming a non-cutting edge, with a bevel extending from its cuttingedge to its non-cutting edge. Accordingly, the second jaw displaces themale lip and female channel more significantly proximate its cuttingedge than proximate its non-cutting edge.

In the preferred form of the invention, the third jaw likewise includesa first side forming the cutting edge thereof and an opposing secondside that forms a non-cutting edge. As the actuator closes the jaws, thenon-cutting edges of the second and third jaws begin to approach oneanother. However, at least in one preferred embodiment, the non-cuttingedges of the second and third jaws do not slide past each other when theactuator closes the jaws, but rather remain spaced apart from each otherat such closed position.

Another aspect of the present invention relates to a novel method offorming an attachment in an interlocking side-lapped seam of such asteel deck structure. In practicing such method, the upturned male lipof the first steel deck panel is engaged within the downwardly-directedU-shaped female channel of the second steel deck panel. A first jawhaving a cutting edge is positioned proximate the first wall of thefemale channel. A second jaw having a cutting edge is positionedproximate the second wall of the female channel. This second jaw isdisposed proximate to the first jaw, and generally facing the first jaw,but is laterally offset therefrom. A third jaw having a cutting edge ispositioned proximate to the first wall of the female channel, and spacedapart from the first jaw. A fourth jaw having a cutting edge ispositioned proximate to the second wall of the female channel, proximateto the third jaw, and generally facing the third jaw, but laterallyoffset therefrom. The cutting edges of the first and second jaws areselectively moved generally toward each other from an open position to aclosed position for causing their respective cutting edges to at leastpartially pass each other to cut a first slot through the U-shapedchannel and the male lip received thereby. Likewise, the cutting edgesof the third and fourth jaws are selectively moved generally toward eachother from the open position to the closed position, for causing theirrespective cutting edges to at least partially pass each other to cut asecond slot through the U-shaped channel and the male lip receivedthereby. This second slot is laterally spaced from the first slot.

In the preferred form of such method, these steps of selectively movingthe cutting edges of the first and second jaws toward each other, andselectively moving the cutting edges of the third and fourth jaws towardeach other, are performed synchronously. Ideally, the first jaw isspaced apart from the third jaw, and the fourth jaw is spaced apart fromsecond jaw. Preferably, in the vicinity of the first slot, the first jawdeforms the upturned male lip and U-shaped female channel in a firstdirection, and the second jaw deforms the upturned male lip and U-shapedfemale channel in a second, opposite direction. Similarly, at the secondslot, the third jaw deforms the upturned male lip and U-shaped femalechannel in the first direction, and the fourth jaw deforms the upturnedmale lip and U-shaped female channel in the second, opposite direction.

When selectively moving the cutting edges of the first and second jawsgenerally toward each other, the cutting edges of the first and secondjaws are moved within first and second respective planes. These firstand second planes may either be generally co-planar or spaced apart fromeach other. Likewise, when selectively moving the cutting edges of thethird and fourth jaws generally toward each other, the cutting edges ofthe third and fourth jaws are moved within third and fourth respectiveplanes, and these third and fourth planes may either be generallyco-planar with each other or spaced apart from each other.

In practicing the aforementioned method, the first, second, third andfourth jaws are preferably mounted for rotation about a common pivotaxis. In this regard, the first and third jaws are preferably coupled toeach other for synchronized movement with each other, and the second andfourth jaws are preferably coupled to each other for synchronizedmovement with each other. In addition, the method preferably includesthe steps of disposing the second jaw generally between the first andthird jaws, and disposing the third jaw generally between the second andfourth jaws.

In one embodiment, such method includes the further steps of forming thecutting edge of the first jaw on a first side of the first jaw, leavingthe opposing second side as a non-cutting edge, and forming a bevel onthe first jaw extending from its cutting edge toward its non-cuttingedge. Thus, as the jaws close, the cutting edge of the first jaw extendsfurther into the side-lapped seam than the non-cutting edge thereof. Asa result, the first jaw displaces the male lip and female channel moresignificantly proximate its cutting edge than proximate its non-cuttingedge. Similarly, the method may include the steps of forming the cuttingedge of the second jaw on a first side of the second jaw, leaving theopposing second side as a non-cutting edge, and

forming a bevel on the second jaw extending from its cutting edge towardits non-cutting edge for causing the cutting edge of the second jaw toextend further into the side-lapped seam than the non-cutting edge. Thesecond jaw thereby displaces the male lip and female channel moresignificantly proximate its cutting edge than proximate its non-cuttingedge when the jaws are closed.

In one preferred form of practicing such attachment method, the thirdjaw is also formed to have a cutting edge on one side and a non-cuttingedge on its opposing second side. As the jaws are moved from theiropened to closed position, the non-cutting edges of the second and thirdjaws are maintained spaced apart from each other even as the cuttingedges of the first and second jaws partially slide past each other. As aresult, in such embodiment, no additional slot is formed between thesecond and third jaws.

Another aspect of the present invention relates to the steel deckstructure, incorporating an interlocking side-lapped seam, that resultsfrom the use of the above-described punching tool and/or attachmentmethod. Such a steel deck structure includes a first steel deck panelhaving an upturned male lip along one side edge thereof, and a secondsteel deck panel including a downwardly-directed U-shaped female channelalong one side edge thereof. The U-shaped female channel extends overand receives the upturned male lip of the first steel deck panel to formthe side-lapped seam. The U-shaped channel includes first and secondwalls generally parallel to each other. An attachment is formed withinthe side-lapped seam to attach the first and second steel deck panels toeach other. This seam attachment includes first and secondgenerally-vertical cut lines that each extend through the male lip, andthrough the first and second walls of the female channel. These two cutlines generally-vertical cut lines extend generally parallel to eachother and are somewhat spaced apart from each other.

The attachment formed in the side-lapped seam includes a central portionthat lies between the first and second cut lines; this central portionmay be generally continuous and unbroken; alternatively, it may bedeformed to the extent of including a relatively shallow cut. Adjacentthe first cut line, a first outer portion of the attachment is separatedfrom the central portion of the attachment; similarly, adjacent thesecond cut line, a second outer portion of the attachment is separatedfrom the central portion of the attachment.

The central portion of the attachment that lies adjacent the first cutline is deformed in a first direction; on the other hand, the centralportion of the attachment that lies adjacent the second cut line isdeformed in a second opposing direction. The first outer portion of theattachment, lying adjacent the first cut line, is deformed in the seconddirection. Conversely, the second outer portion of the attachment isdeformed in the first direction. These attachments can be formed atregular intervals along the side-lapped seam to securely attach thefirst and second steel deck panels together.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a steel deck diaphragm formed by twosteel deck panels forming a side-lapped seam along their common edges.

FIG. 2 is a front view of the working end of a punching tool using twosets of opposing pivotally-mounted jaws in accordance with the presentinvention.

FIG. 3 is an enlarged perspective view of the sidelapped seam portionjoining the edges of two adjacent steel deck panels after being punchedtwice with the tool of FIG. 2.

FIG. 3A is a cross-sectional view of the side-lapped seam shown in FIG.3 taken through the plane indicated by lines 3A-3A in FIG. 3 andillustrating the first and second slots formed in the side-lapped seamby the punching tool of FIG. 2.

FIG. 4 is an enlarged rear view of the jaws of the punching tool shownin FIG. 2 in their opened position.

FIG. 5 is an enlarged front view of the jaws of the punching tool shownin FIG. 2 in their closed position.

FIG. 6 is a top view of one of the four jaws that are mounted in thepunching tool of FIG. 2, including a common pivot axle hole andincluding a beveled cutting edge.

FIG. 7 is an enlarged side view of first, second, third, and fourth jawsof the punching tool shown in FIG. 2 each mounted for pivotal rotationabout a connecting pivot axle bolt.

FIG. 8 is a perspective view of the first, second, third, and fourthjaws of the punching tool shown in FIG. 2 in their opened position.

FIG. 9 is a perspective view of the first, second, third, and fourthjaws of the punching tool shown in FIG. 2 in their closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a steel deck structure is designated generally byreference numeral 10 and includes at least a first fluted steel deckpanel 12 and a second fluted steel deck panel 14. Deck panels 12 and 14are welded or otherwise fastened to, and supported by, underlyinghorizontal steel support beams 16. In turn, horizontal steel supportbeams 16 are welded to, and supported by, vertical steel framing members18, as is known in the art. Steel deck panels 12 and 14 are joined alonga common longitudinal edge by a side-lapped seam 20, the details ofwhich are described below. It will be sufficient to note here thatside-lapped seam 20 should be secured in a manner which not onlyprevents the common longitudinal edges of panels 12 and 14 fromseparating from each other, but also prevents such common longitudinaledges of panels 12 and 14 from slipping or sliding longitudinallyrelative to each other.

Turning to FIG. 2, a punching tool constructed in accordance with theteachings of the present invention is designated generally by referencenumeral 22. Punching tool 22 includes a first fixed support bracket 24and a second complementary fixed support bracket 26 (see FIG. 7).Referring briefly to FIG. 7, a set of four cutting arms 28, 30, 32 and34 are secured for pivotal rotation between fixed support brackets 24and 26. A common pivot axle bolt 36, secured by a mating nut 38, extendsthrough aligned apertures formed in brackets 24 and 26, and formed incutting arms 28, 30, 32 and 34, for allowing cutting arms 28, 30, 32 and34 to pivot relative to fixed support brackets 24 and 26. Each of thefour cutting arms 28, 30, 32 and 34 has a first end forming a cuttingjaw; the cutting jaws are collectively designated by reference numeral40 in FIG. 2.

As shown in FIG. 2, the second end 42 of cutting arm 28 is pivotallysecured to a first end of link 44 by a pivot bolt 46. While hidden fromview in FIG. 2, the second end of cutting arm 32 (see FIG. 7) islikewise pivotally secured to the first end of link 44 by pivot bolt 46.The second end 48 of cutting arm 30, and the second end of cutting arm34 (see FIG. 7), are both pivotally secured to a first end link 50 bypivot bolt 52. The second ends of links 44 and 52 are both pivotallysecured to a slide-action drive bolt 54 that reciprocates within slot 56of fixed support brackets 24 and 26. As drive bolt 54 is actuated withinslot 56 toward pivot bolt/nut 36/38, links 44 and 50 cause the secondends 42 and 48 of cutting arms 28 and 30 to rotate outwardly away fromsupport brackets 24 and 26. This in turn causes cutting jaws 40 to pivotfrom their opened position (shown in FIG. 2) to their closed position.Conversely, when drive bolt 54 is de-actuated within slot 56 away frompivot bolt/nut 36/38, cutting jaws 40 open back up.

The precise mechanism for powering the reciprocation of drive bolt 54 toopen and close cutting jaws 40 need not be described herein. It shouldbe sufficient to note that suitable apparatus for controlling andpowering reciprocation of drive bolt 54 by hydraulic means is disclosedin prior U.S. Pat. No. 5,878,617 to Parker, the contents of which arehereby incorporated herein by reference. Of course, the actuator used toreciprocate drive bolt 54 need not be hydraulic or pneumatic; forexample, an electric motor could also be used to advance and retractdrive bolt 54.

Referring now to FIG. 3, an abbreviated portion of the interlockingside-lapped seam 20 of FIG. 1 is illustrated in greater detail followingtwo applications of the punching tool of FIG. 2.

Steel deck panel 14 includes an upturned male lip 58 along one side edgethereof. Steel deck panel 12 includes a downwardly-directed U-shapedfemale channel 60 along one side edge thereof for receiving the upturnedmale lip 58 of steel deck panel 14. U-shaped channel 60 includes a firstupwardly-directed wall 62; as upwardly-directed wall 62 reaches itspeak, it curves through an arc of 180 degrees, extending downwardly toform a second wall 64. First wall 62 and second wall 64 extend generallyparallel to each other, and are spaced apart from each other by asufficient gap to permit upwardly-directed male lip 58 to be insertedtherein. U-shaped female channel 60 of steel deck panel 12 extends overand receives upturned male lip 58 of steel deck panel 14 to form theside-lapped seam 20.

Still referring to FIG. 3, a first actuation of punching tool 22 to seam20 produces a first pair of slots, or vertical cut lines, 65 and 66.Also shown in FIG. 3 are a second pair of slots 68 and 70, which areproduced by a second actuation of punching tool 22 to seam 20. Verticalcut line 65 extends through male lip 58 and through first and secondwalls 62 and 64 of the female channel 60. Likewise, vertical cut line 66extends through male lip 58 and through first and second walls 62 and 64of female channel 60. Vertical cut lines 65 and 66 extend generallyparallel to each other and are slightly spaced apart from each other.

The application of punching tool 22 to seam 20 not only forms slots 65and 66; it also produces opposing conical deformations in seam 20 oneither side of such slots. Referring to the sectional view of FIG. 3A,the attachment formed by a first actuation of punching tool 22 includesvertical cut lines 65 and 66. A central portion of such attachment,lying between the first and second cut lines 65 and 66, is designated byreference numeral 72. In the illustrated embodiment, central portion 72is continuous and unbroken between cut lines 65 and 66. A first outerportion 74 of the attachment lies adjacent first cut line 65 on a sidethereof opposite central portion 72 of the attachment. Likewise, asecond outer portion 76 of the attachment lies adjacent second cut line66 on a side thereof opposite central portion 72 of the attachment.

Central portion 72 of the attachment is deformed in a first direction(i.e., to the right relative to FIG. 3A) adjacent first cut line 65;central portion 72 of the attachment is deformed in a second, oppositedirection (i.e., to the left relative to FIG. 3A) adjacent second cutline 66. First outer portion 74 of the attachment is deformed in theaforementioned second direction (i.e., to the left relative to FIG. 3A);conversely, second outer portion 76 of the attachment is deformed in thefirst direction (i.e., to the right relative to FIG. 3A). The resultingattachment securely fastens side-lapped seam 20 together. Moreover,initial testing appears to show that such attachment provides higherhorizontal shear values than, for example, those obtained by using theattachment shown in U.S. Pat. No. 6,397,469 to Parker. It is theorizedthat such initial higher test values may result from the shape andconfiguration of the above-described conical deformed regions thatresult adjacent vertical slots 65 and 66.

The actual cutting jaws, collectively represented by reference numeral40 in FIG. 2, are best illustrated in FIGS. 4-9. A first cutting jaw 78is formed on the end of cutting arm 28, and includes a cutting edge 80for engaging one of the walls (e.g., wall 64) of the female channel 20.A second cutting jaw 82 is formed on the end of cutting arm 30 and has acutting edge 84 for engaging the opposite wall (e.g., wall 62) of femalechannel 20. Second jaw 82 is disposed proximate first jaw 78 but islaterally offset therefrom. Cutting edge 80 of jaw 78 generally facescutting edge 84 of second jaw 82. Cutting edge 80 sweeps through a firstplane, and cutting edge 84 sweeps through a second plane; these twoplanes may be generally co-planar, separated only by a small gap topermit the cutting edges to pass each other in the closed position.Alternatively, these first and second planes may be intentionally spacedapart, as by inserting a spacing washer or the like between jaws 78 and82 to increase twisting deformation of the seam adjacent first slot 65.In the view shown in FIG. 4, first and second jaws 78 and 82 are openedapart from each other; in the view shown in FIG. 5, first and secondjaws 78 and 82 are closed, wherein portions of their respective cuttingedges 80 and 84 partially pass by each other as the actuator drive bolt54 (see FIG. 2) closes first and second jaws 78 and 82 for cutting firstslot 65 through the U-shaped channel 60 and male lip 58 of seam 20.

A third cutting jaw 86 is formed on the end of cutting arm 32, andincludes a cutting edge 88 for engaging one of the walls (e.g., wall 64)of female channel 20. A fourth cutting jaw 90 is formed on the end ofcutting arm 34 and has a cutting edge 92 for engaging the opposite wall(e.g., wall 62) of female channel 20. Fourth jaw 90 is disposedproximate third jaw 86 but is laterally offset therefrom. Cutting edge88 of third jaw 86 generally faces cutting edge 92 of fourth jaw 90. Inthe view shown in FIG. 4, third and fourth jaws 86 and 90 are openedapart from each other; in the view shown in FIG. 5, third and fourthjaws 86 and 90 are closed, wherein portions of their respective cuttingedges 88 and 92 partially pass by each other as the actuator drive bolt54 (see FIG. 2) closes third and fourth jaws 86 and 90 for cuttingsecond slot 66 through the U-shaped channel 60 and male lip 58 of seam20. As explained above, actuator drive bolt 54, and links 44 and 50 (seeFIG. 2), close third and fourth jaws 86 and 90 at the same time that itcloses first and second jaws 78 and 82.

As noted above, cutting arms 28, 30, 32 and 34 are all mounted forpivotal rotation about pivot axle bolt 36 secured by nut 38.Consequently, first jaw 78, second jaw 82, third jaw 86, and fourth jaw90 are mounted for rotation about a common pivot axis. Referring brieflyto FIG. 6, first cutting arm 28 is shown with cutting jaw 78, andcutting edge 80, formed at one end thereof. Pivot hole 94 is formed nearjaw 78 for receiving pivot axle bolt 36. In addition, hole 96 is formedat second end 42 of cutting arm 28 to receive the pivot bolt 46 forattachment to link 44. Cutting arms 28 and 32 are preferably bothcoupled to pivot bolt 46, thereby coupling first and third jaws 78 and86 to each other for synchronized movement. Likewise, cutting arms 30and 34 are preferably both coupled to pivot bolt 52, thereby couplingsecond and fourth jaws 86 and 90 to each other for synchronizedmovement. In the preferred embodiment illustrated, second jaw 82 isdisposed generally between first and third jaws 78 and 86, and third jaw86 is disposed generally between second and fourth jaws 82 and 90.

Referring to FIGS. 4-9, and as explained above, each of cutting jaws 78,82, 86, and 90 has a cutting edge 80, 84, 88, and 92, respectively. Inone preferred embodiment of the present invention, each of these cuttingjaws includes an opposing non-cutting edge. For example, cutting jaw 78includes an outer non-cutting edge 81 on an opposite side from cuttingedge 80. Similarly, cutting jaw 82 includes a non-cutting edge 85 on anopposite side from cutting edge 84; cutting jaw 86 includes anon-cutting edge 89 on an opposite side from cutting edge 88; andcutting jaw 90 includes an outer non-cutting edge 93 on an opposite sidefrom cutting edge 92.

As shown in FIGS. 4-9, a bevel is preferably formed on each cutting jawextending from the cutting edge inwardly toward the non-cutting edgethereof. Thus, a bevel is formed upon the end of cutting jaw 78extending from cutting edge 80 inwardly toward non-cutting edge 81.Accordingly, when the cutting jaws are closed over seam 20 of steel deckstructure 10, cutting jaw 78 displaces male lip 58 and female channel 60to a greater extent proximate cutting edge 80 than proximate non-cuttingedge 81. Similarly, a bevel is formed upon the end of cutting jaw 82extending from cutting edge 84 inwardly toward non-cutting edge 85.Consequently, when the cutting jaws are closed over seam 20 of steeldeck structure 10, cutting jaw 82 displaces male lip 58 and femalechannel 60 to a greater extent proximate cutting edge 84 than proximatenon-cutting edge 85. Thus, the cutting forces exerted by cutting jaws 78and 82, when cutting slot 65 in seam 20, are concentrated along thecutting edges 80 and 84 thereof, and very little, if any, force isexerted on seam 20 by the non-cutting edges 81 and 85 thereof. Similarbevels may be preferably formed upon the third cutting jaw 86 and fourthcutting jaw 90 to facilitate the cutting of slot 66. The aforementionedbevels are illustrated in the patent drawings as straight line bevels,without any curvature; if desired, such bevels can be formed to have adegree of concavity to make the cutting edges sharper.

Referring to FIG. 7, it will be noted that the non-cutting edge 89 ofthird cutting jaw 86 is generally proximate the non-cutting edge 85 ofsecond cutting jaw 82. It will also be noted that, in the embodimentillustrated in FIG. 7, a spacing washer, or shim, 98 is inserted betweencutting arm 30 and cutting arm 32 along pivot axle bolt 36. The combinedeffect of the aforementioned bevels, plus the additional spacing betweenthe second and third cutting jaws, lessens the likelihood of shearingthe seam, as the jaws are closed, within central portion 72 (see FIG.3A) of the seam attachment. Even though the second jaw 82 and third jaw86 partially travel past each other as the jaws are closed, theaforementioned bevels, coupled with the additional spacing between thesecond and third jaws, reduces or eliminates any shearing force exertedon the seam between the second and third jaws 82 and 86, respectively.

On the other hand, should it be desired to create additional deformationwithin the attachment, particularly within central portion 72 of theattachment, then spacing washer 98 can be omitted, thereby allowing the“non-cutting” edges 85 and 89 to pass more closely toward each other asthe jaws are closed to exert a greater twisting force upon centralportion 72 of the attachment. In this regard, even if the second andthird jaws actually form a shallow cut through seam 20 (in which case,the so-called “non-cutting edges” 85 and 89 might more accurately beconsidered as “secondary cutting edges”), this shallow cut will not beformed until the jaws are almost fully closed, whereas the cut lines 65and 66 are at least partially formed well before the jaws reach fullclosure. Therefore, neither the second jaw nor the third jaw isattempting to cut more than one cut line at any given moment duringclosure of the jaws.

As noted above, one aspect of the present invention relates to the novelmethod of forming the seam attachment described above. In practicingsuch method, upturned male lip 58 of deck panel 14 is engaged within thedownwardly-directed U-shaped female channel 60 of deck panel 12. Firstjaw 78, second jaw 82, third jaw 86 and fourth jaw 90 are inserted intopunching tool 22, and the opened jaws are inserted over and around seam20. Preferably, first jaw 78, second jaw 82, third jaw 86, and fourthjaw 90 are mounted for pivotal rotation about a common pivot axis, suchas pivot bolt axle 36. In this regard, first and third jaws 78 and 86are preferably pivoted as a unit (as by link 44) for synchronizedmovement with each other, and second and fourth jaws 82 and 90 arepreferably pivoted as a unit (as by link 50) for synchronized movementwith each other. First jaw 78 and third jaw 86 are positioned proximateone wall (e.g., wall 64) of female channel 60, and second jaw 82 andfourth jaw 90 are positioned proximate a second wall (e.g., wall 62) offemale channel 60. Alternatively, the tool can be reversed, and thefirst and third jaws 78 and 86 can be positioned proximate wall 62,while the second and fourth jaws 82 and 90 are positioned proximate wall64. While it is not necessary, the punching tool can be periodicallyreversed as an operator periodically forms attachments along seam 20 toreverse the directions in which the seam is deformed.

After placing the opened jaws over seam 20, the tool operator thenactuates punching tool 22 to force the cutting edges 80 and 84 of firstand second jaws 78 and 82 generally toward each other from an openposition to a closed position, at least partially passing each other tocut first slot 65 through seam 20. Concurrently, cutting edges 88 and 92of third and fourth jaws 86 and 90 are forced generally toward eachother from the open position to the closed position, at least partiallypassing each other to cut second slot 66 through seam 20, spaced apartslightly from first slot 65. Ideally, first jaw 78 is spaced apart fromthird jaw 86 (as by second jaw 82), and fourth jaw 90 is spaced apartfrom second jaw 82 (as by third jaw 86).

In practicing this method of forming the attachment, it is preferredthat first jaw 78 deforms upturned male lip 58 and U-shaped femalechannel 60 in a first direction proximate cut line 65, and that secondjaw 82 deforms upturned male lip 58 and U-shaped female channel 60 inthe opposite direction, as illustrated in FIG. 3A. Similarly, at secondslot 66, it is preferred that third jaw 86 deforms upturned male lip 58and U-shaped female channel 60 in the first direction, and that thefourth jaw 90 deforms upturned male lip 58 and U-shaped female channel60 in the second, opposite direction.

When selectively moving cutting edges 80 and 84 of first and second jaws78 and 82 generally toward each other, cutting edges 80 and 84 are movedwithin first and second respective planes. In one preferred embodiment,cutting edges 80 and 84 are moved through first and second planes thatare generally co-planar; in other embodiments, these first and secondplanes are spaced apart, as by inserting a spacing washer or shimbetween first and second cutting arms 28 and 30 along pivot axle bolt36. Likewise, cutting edges 88 and 92 of third and fourth jaws 86 and 90are moved within third and fourth respective planes; these third andfourth respective planes may either be generally be co-planar with eachother, or purposely spaced apart by a spacing washer, if desired.

The method of forming the above-described attachment avoids loading bothside edges of any particular jaw at the same point in time. In thisregard, the method preferably includes the step of forming a primarycutting edge 80 on a first side of first jaw 78, leaving the opposingsecond side as a non-cutting edge or secondary cutting edge 81, andforming a bevel on first jaw 78 extending from cutting edge 80 towardopposite edge 81. Preferably, the same steps are used in forming thesecond, third and fourth jaws 82, 86 and 90. The method of the presentinvention may further include placement of spacing washer, shims or thelike (see 98 in FIG. 7) between one or more of the cutting jaws, eitherto lessen the likelihood of shearing (as between jaws 82 and 86) or toincrease the amount of twisting deformation about vertical cut lines 65and 66 (as between jaws 78 and 84, and as between jaws 86 and 90).

Those skilled in the art will now appreciate that an improved punchingtool has been described for forming an attachment in an interlockingside-lapped seam of a steel deck structure which provides a solidattachment capable of resisting significant horizontal shear loads. Thedisclosed punching tool can be operated relatively quickly and easily bya deck installer to attach interlocking side-lapped seams of a steeldeck structure. The resulting attachment that can be quickly and easilyinspected by an inspector standing atop the assembled steel decking.Moreover, the disclosed punching tool includes a cutting blade assemblythat equalizes the wear on the blades, thereby avoiding excessive stresson any particular blade, and extending the usable life of the tool. Inaddition, the disclosed method of forming such side-lapped seamattachment, and the resulting seam attachment structure, provides higherhorizontal shear loading values, more resistant to slippage whensubjected to a horizontal load, than those methods already known.

While the present invention has been described with respect to preferredembodiments thereof, such description is for illustrative purposes only,and is not to be construed as limiting the scope of the invention.Various modifications and changes may be made to the describedembodiments by those skilled in the art without departing from the truespirit and scope of the invention as defined by the appended claims.

1. A punching tool for forming an attachment in an interlockingside-lapped seam of a steel deck structure, the steel deck structureincluding at least first and second steel deck panels, the first steeldeck panel including an upturned male lip along one side edge thereof,the second steel deck panel including a downwardly-directed U-shapedfemale channel along one side edge thereof for receiving the upturnedmale lip of the first steel deck panel, the U-shaped channel includingfirst and second walls generally parallel to each other, the punchingtool comprising: a. a first jaw having a cutting edge for engaging thefirst wall of the female channel; b. a second jaw having a cutting edgefor engaging the second wall of the female channel, the second jaw beingdisposed proximate the first jaw but laterally offset therefrom, andgenerally facing the first jaw; c. an actuator coupled to the first andsecond jaws for selectively moving the cutting edges of the first andsecond jaws generally toward each other to a closed position, or awayfrom each other to an open position, the cutting edges of the first andsecond jaws at least partially passing each other as the actuator movesthe first and second jaws to the closed position for cutting a firstslot through the U-shaped channel and the male lip received thereby; d.a third jaw having a cutting edge for engaging the first wall of thefemale channel; e. a fourth jaw having a cutting edge for engaging thesecond wall of the female channel, the fourth jaw being disposedproximate the third jaw but laterally offset therefrom, and generallyfacing the third jaw; f. the actuator also being coupled to the thirdand fourth jaws for selectively moving the cutting edges of the thirdand fourth jaws generally toward each other to a closed position at thesame time that the actuator moves the cutting edges of the first andsecond jaws generally toward each other to the closed position, theactuator moving the cutting edges of the third and fourth jaws away fromeach other to an open position at the same time that the actuator movesthe cutting edges of the first and second jaws away from each other tothe open position, the cutting edges of the third and fourth jaws atleast partially passing each other as the actuator moves the third andfourth jaws to the closed position for cutting a second slot through theU-shaped channel and the male lip received thereby, the second slotbeing laterally spaced from the first slot.
 2. The punching tool recitedby claim 1 wherein: a. the cutting edge of the first jaw is moved by theactuator within a first plane; b. the cutting edge of the second jaw ismoved by the actuator within a second plane; and c. the first and secondplanes are generally co-planar.
 3. The punching tool recited by claim 2wherein: a. the cutting edge of the third jaw is moved by the actuatorwithin a third plane; b. the cutting edge of the fourth jaw is moved bythe actuator within a fourth plane; and c. the third and fourth planesare generally co-planar.
 4. The punching tool recited by claim 1 whereinthe first, second, third and fourth jaws are mounted for rotation abouta common pivot axis.
 5. The punching tool recited by claim 1 wherein thefirst and third jaws are generally coupled to each other forsynchronized movement with each other, and wherein the second and fourthjaws are generally coupled to each other for synchronized movement witheach other.
 6. The punching tool recited by claim 1 wherein the secondjaw is disposed generally between the first and third jaws, and whereinthe third jaw is disposed generally between the second and fourth jaws.7. The punching tool recited by claim 1 wherein the first jaw includes afirst side forming the cutting edge thereof and an opposing second sidethat forms a non-cutting edge, the first jaw being beveled from thecutting edge to the non-cutting edge whereby the first jaw displaces themale lip and female channel more significantly proximate the cuttingedge of the first jaw than proximate the non-cutting edge of the firstjaw.
 8. The punching tool recited by claim 7 wherein the second jawincludes a first side forming the cutting edge thereof and an opposingsecond side that forms a non-cutting edge, the second jaw being beveledfrom the cutting edge thereof to the non-cutting edge thereof wherebythe second jaw displaces the male lip and female channel moresignificantly proximate the cutting edge of the second jaw thanproximate the non-cutting edge of the second jaw.
 9. The punching toolrecited by claim 1 wherein: a. the second jaw includes a first sideforming the cutting edge thereof and an opposing second side that formsa non-cutting edge; b. the third jaw includes a first side forming thecutting edge thereof and an opposing second side that forms anon-cutting edge; and c. the cutting edges of the first and second jawsbeing spaced apart from each other when the actuator moves the first,second, third, and fourth jaws to the open position, the non-cuttingedges of the second and third jaws also being spaced apart from eachother at such open position; and d. the cutting edges of the first andsecond jaws at least partially overlapping each other when the actuatormoves the first, second, third, and fourth jaws to the closed position,the non-cutting edges of the second and third jaws remaining spacedapart from each other at such closed position.
 10. The punching toolrecited by claim 1 wherein the cutting edges of the first, second,third, and fourth jaws each lie adjacent a beveled surface.
 11. Apunching tool for forming an attachment in an interlocking side-lappedseam of a steel deck structure, the steel deck structure including atleast first and second steel deck panels, the first steel deck panelincluding an upturned male lip along one side edge thereof, the secondsteel deck panel including a downwardly-directed U-shaped female channelalong one side edge thereof for receiving the upturned male lip of thefirst steel deck panel, the U-shaped channel including first and secondwalls generally parallel to each other, the punching tool comprising: a.a first pair of jaws each having a cutting edge for engaging the firstwall of the female channel; b. a second pair of jaws each having acutting edge for engaging the second wall of the female channel, thesecond pair of jaws generally facing the first pair of jaws, each of thejaws in said second pair being disposed proximate one of the jaws insaid first pair but being laterally offset therefrom; c. an actuatorcoupled to the first and second pairs of jaws for selectively moving thecutting edges of the first and second pairs of jaws generally towardeach other to a closed position, or away from each other to an openposition, the cutting edges of the first pair of jaws at least partiallypassing the cutting edges of the second pair of jaws as the actuatormoves the first and second pairs of jaws to the closed position forcutting at least first and second slots through the U-shaped channel andthe male lip received thereby, the second slot being laterally spacedfrom the first slot.
 12. The punching tool recited by claim 11 whereinthe first and second pairs of jaws are mounted for rotation about acommon pivot axis.
 13. The punching tool recited by claim 11 wherein thefirst pair of jaws are generally coupled to each other, and wherein thesecond pair of jaws are generally coupled to each other for synchronizedmovement with each other relative to the first pair of jaws.
 14. Thepunching tool recited by claim 11 wherein at least one of the jaws inthe second pair of jaws is disposed generally between the first pair ofjaws when the actuator moves the cutting edges of the first and secondpairs of jaws to the closed position.
 15. The punching tool recited byclaim 14 wherein at least one of the jaws in the first pair of jaws isdisposed generally between the second pair of jaws when the actuatormoves the cutting edges of the first and second pairs of jaws to theclosed position.
 16. The punching tool recited by claim 11 wherein eachof the jaws in the first pair of jaws includes a first side forming thecutting edge thereof and an opposing second side that forms anon-cutting edge, each of the jaws in the first pair of jaws beingbeveled from the cutting edge to the non-cutting edge whereby each ofthe jaws in the first pair of jaws displaces the male lip and femalechannel more significantly proximate the cutting edge of such jaw thanproximate the non-cutting edge of such jaw.
 17. The punching toolrecited by claim 16 wherein each of the jaws in the second pair of jawsincludes a first side forming the cutting edge thereof and an opposingsecond side that forms a non-cutting edge, each of the jaws in thesecond pair of jaws being beveled from the cutting edge thereof to thenon-cutting edge thereof whereby each of the jaws in the second pair ofjaws displaces the male lip and female channel more significantlyproximate the cutting edge of such jaw than proximate the non-cuttingedge of the such jaw.